But in touristy cities with housing shortages and hot real-estate markets—New York, San Francisco, Los Angeles, and many more—Airbnb plays a less savory role. Not only does Airbnb facilitate illegal conversions of entire buildings from tenant apartments to de facto hotels, it has also become part of the landlord lobby that resists enforcement of local laws prohibiting such abuses. To be sure, places like San Francisco would suffer the effects of conversions even without Airbnb, but the evidence shows that Airbnb supercharges the process....

Not surprisingly then, the Airbnb-ing of San Francisco is part of what Tenderloin Housing Clinic Executive Director Randy Shaw has called a “massive rezoning of the entire city for tourist use.” Ted Gullicksen, who was executive director of the San Francisco Tenants Union, said, “We call it the ‘hotelization’ of San Francisco. Seniors, families, and low-income tenants are being pushed out.”

But here’s what’s deceptive about that framing: Data analysis of Airbnb usage in San Francisco tells a decidedly different story about who is benefitting. Although Airbnb refuses to share its numbers, a 2014 report commissioned by the San Francisco Chronicle found that of the (at the time) nearly 5,000 homes, apartments, and private or shared rooms for rent via Airbnb, two-thirds were entire houses or apartments with no owner present during the rental period, and almost a third of Airbnb rentals were controlled by people with two or more listings. Some of the “whole house” or “whole apartment” rentals are from hosts who happen to be away. But many others are being rented out by professional property managers who are handling multiple Airbnb rentals on behalf of absentee home- and condo owners. A separate study conducted by data analyst Tom Slee found similar results. He calculated that about 70 percent of Airbnb revenue comes from hosts who are renting out an entire home or apartment, and 40 percent comes from Airbnb hosts with multiple listings.

In other words, a great deal of Airbnb’s revenue and commercial activity in San Francisco does not come from the listings of “regular people” who own and live in their homes and are merely renting out a spare room. Instead, an increasing amount comes from the types of professional landlords who are removing housing from the market and making it exclusively available for tourists. Many of these landlords are getting rid of rent-controlled housing, and are even evicting thousands of people like Chris Butler, Susan Whetzel, Theresa Flandrich, and her neighbors. It would be useful to know how the number of Airbnb de facto hotel rooms in San Francisco and elsewhere compares with bona fide host rentals. But, of course, the company won’t share that data.